dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fanotify: notify on mount attach and detach

Browse Source 
Add notifications for attaching and detaching mounts.  The following new
event masks are added:

  FAN_MNT_ATTACH  - Mount was attached
  FAN_MNT_DETACH  - Mount was detached

If a mount is moved, then the event is reported with (FAN_MNT_ATTACH |
FAN_MNT_DETACH).

These events add an info record of type FAN_EVENT_INFO_TYPE_MNT containing
these fields identifying the affected mounts:

  __u64 mnt_id    - the ID of the mount (see statmount(2))

FAN_REPORT_MNT must be supplied to fanotify_init() to receive these events
and no other type of event can be received with this report type.

Marks are added with FAN_MARK_MNTNS, which records the mount namespace from
an nsfs file (e.g. /proc/self/ns/mnt).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Link: https://lore.kernel.org/r/20250129165803.72138-3-mszeredi@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Miklos Szeredi
2025-02-05 17:21:07 +01:00
committed by Christian Brauner
parent b944249bce
commit 0f46d81f2b
8 changed files with 164 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/uapi/linux/fanotify.h
+10
View File
@@ -28,6 +28,8 @@
/* #define FAN_DIR_MODIFY 0x00080000 */ /* Deprecated (reserved) */
#define FAN_PRE_ACCESS 0x00100000 /* Pre-content access hook */
#define FAN_MNT_ATTACH 0x01000000 /* Mount was attached */
#define FAN_MNT_DETACH 0x02000000 /* Mount was detached */
#define FAN_EVENT_ON_CHILD 0x08000000 /* Interested in child events */
@@ -64,6 +66,7 @@
#define FAN_REPORT_NAME 0x00000800 /* Report events with name */
#define FAN_REPORT_TARGET_FID 0x00001000 /* Report dirent target id */
#define FAN_REPORT_FD_ERROR 0x00002000 /* event->fd can report error */
#define FAN_REPORT_MNT 0x00004000 /* Report mount events */
/* Convenience macro - FAN_REPORT_NAME requires FAN_REPORT_DIR_FID */
#define FAN_REPORT_DFID_NAME (FAN_REPORT_DIR_FID | FAN_REPORT_NAME)
@@ -94,6 +97,7 @@
#define FAN_MARK_INODE 0x00000000
#define FAN_MARK_MOUNT 0x00000010
#define FAN_MARK_FILESYSTEM 0x00000100
#define FAN_MARK_MNTNS 0x00000110
/*
* Convenience macro - FAN_MARK_IGNORE requires FAN_MARK_IGNORED_SURV_MODIFY
@@ -147,6 +151,7 @@ struct fanotify_event_metadata {
#define FAN_EVENT_INFO_TYPE_PIDFD 4
#define FAN_EVENT_INFO_TYPE_ERROR 5
#define FAN_EVENT_INFO_TYPE_RANGE 6
#define FAN_EVENT_INFO_TYPE_MNT 7
/* Special info types for FAN_RENAME */
#define FAN_EVENT_INFO_TYPE_OLD_DFID_NAME 10
@@ -200,6 +205,11 @@ struct fanotify_event_info_range {
__u64 count;
};
struct fanotify_event_info_mnt {
struct fanotify_event_info_header hdr;
__u64 mnt_id;
};
/*
* User space may need to record additional information about its decision.
* The extra information type records what kind of information is included.